Form Designer not showing for .NET 6 project

Environment

Visual Studio Enterprise 17.3.6

.NET version

.NET 6

Did this work in a previous version of Visual Studio and/or previous .NET release?

No response

Issue description

When I open the Form Designer, it is blank. This happens even for a new project. It happens for .NET 6 projects, but the form designer works fine if I create a .NET 4.7.2 project.

I’ve tried all the suggestions in the troubleshooting guide - timeout, antivirus & confirming UseLegacyPathHandling is disabled.

I’ve also tried repairing Visual Studio using the Visual Studio Installer.

Using Task Manager, I can see that the OOP designer (DesignToolsServer.exe) starts, but then closes almost immediately. A while later Visual Studio shows Timed out while connecting to named pipe which I presume is due to DesignToolsServer.exe not being there to respond.

Is there a way to see the output of DesignToolsServer.exe, to work out why it’s closing?

Thanks!

Steps to reproduce

Create new Project: Windows Form App -> .NET 6.0 (though the same happens for .NET 5 and .NET Core 3.1) Double-click Form1.cs

Diagnostics

No response

[Ashley-Li]

@merriemcgaw @dreddy-work @Olina-Zhang Have filed a designer issue : 4743 to track.

[dreddy-work]

@dreddy-work is this a dup of issue: #7609? And you fixed it in designer PR: microsoft/winforms-designer#4578

It is similar but for the supported modes of designer. If you set the unsupported mode for designer ( in this case, HIGHDPIAWARE, equivalent to PermonV2) we cannot proceed with that mode.